Quick Answer. A low hemoglobin count, also known as anemia, is caused by pregnancy, a menstrual period, a diet low in iron, blood loss, or a disease that causes the body to produce fewer red blood cells or to destroy red blood cells. According to the Mayo Clinic, medications also sometimes cause anemia.
A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways.
There are two basic types of T lymphocytes: T-helper cells (CD4+ cells) and T-cytotoxic cells (CD8+ cells). When activated, the T-cytotoxic cells can eliminate the host cells that are infected with virus, Mycobacteria, certain intracellular bacteria, fungi, parasites, and tumor cells.